• 
  Michelle Trachtenberg

  Chloe Payne
• 
  Taylor Schilling

  Veronica Callahan
• 
  Eva Amurri Martino

  Sharra Kelly
• 
  Jennifer Esposito

  Jules Fattore
• 
  Zoe Margaret Colletti

  Cydie
• 
  Michael Imperioli

  Harold Pindus
• 
  Rachel Brosnahan

  Samantha
• 
  Erika Christensen

  Dana Harper McPhearson

• 
  Kate Mulgrew

  Mrs. Jeannie Flanagan
• 
  James Le Gros

  Dr. Dan Harris
• 
  James Van Der Beek

  Dr. Joe Briggs
• 
  Guillermo Díaz

  Nurse Angel Garcia
• 
  Peter Gerety

  Jimmy Flanagan
• 
  Margo Martindale

  Nurse Klowden
• 
  K.K. Moggie

  Dr. Gillian Jelani

• 
  Joey Naber

  (18 episodes, 2009-2010)
• 
  James Tupper

  Dr. Chris Sands
• 
  Patch Darragh

  Tim Flanagan
• 
  Diego Klattenhoff

  Mike Callahan
• 
  Helene Taylor

  Core Nurse
• 
  Jaime Lee Kirchner

  Nurse Sonia Jimenez
• 
  Michael Chernus

  Ryan Flanagan
• 
  Johnny Hopkins

  Bobby Flanagan
• 
  Charles Semine

  Nick Valentino